Chevrolet 2007 Equinox Owner's Manual page 362

Turn the pressure cap slowly counterclockwise
about one-quarter of a turn. If you hear a
hiss, wait for that to stop. This will allow
any pressure still left to be vented out the
discharge hose.
2. Then keep turning the pressure cap slowly,
and remove it.
362
1. You can remove the
coolant surge tank
pressure cap
when the cooling
system, including
the coolant
surge tank pressure
cap and upper
radiator hose,
is no longer hot.
3. Fill the coolant surge tank with the proper
®
DEX-COOL coolant mixture, to the
COLD FILL line.